l82 RE:pORTS 0^ INVESTIGATIONS AND PROJECTS. 



shown that the affinity constant, K, of a tautomeric amide is expressed by 

 the equation, 



// X (Ckz + Cei) ^ (a; + A-, a;) _j^ 



(Ck -\- Ce) I + a; ~ 



in which H is the concentration, in gram molecules per liter, of the hydrogen 

 ions, Cki the concentration of the anions of the keto form, Cei the concen- 

 tration of the anions of the enol form, Ck that of the molecular keto form, 

 Ce that of the molecular enol form, K^, the affinity constant of the keto form, 

 Kz the affinity constant of the enol form, and K^ the ratio of the keto form 

 to the enol form. 



(3) The conditions under which normal and abnormal hydrolysis of salts 

 of tautomeric compounds can be detected have been discussed. 



(4) A large number of derivatives of phenylurazole have been made and 

 studied qualitatively and quantitatively, especially in the light of the theories 

 of tautomeric substances. 



Bancroft, Wilder D., Cornell University, Ithaca, New York. Grant No. 

 411. Systematic study of alloys. (For previous reports see Year Book 

 No. 2, p. xxix; Year Book No. 3, p. 104; Year Book No. 4, pp. 133-134, 

 and Year Book No. 5, p. 141.) $1,000. 



The constitution of the copper-tin bronzes has been determined for tem- 

 peratures above 219° and an account has been pubHshed in the Journal of 

 Physical Chemistry, volume 10, page 630 (1906). There are still some 

 unexplained heat changes at 218° and at 182°. When these have been 

 worked out, the results obtained during the last five years will be presented 

 as a monograph. 



The constitution of the aluminum-copper alloys has been determined and 

 an account has been published in the Journal of Physical Chemistry, volume 

 II, page 425 (1907). There are 6 series of solid solutions and i compound, 

 CuAl,. The p crystals are instable below 566° and the 8 crystals below 

 570°.' 



An account of work on the tensile strength and ductility of cast aluminum 

 bronzes has been published in the Journal of Physical Chemistry, volume 11, 

 page 461 (1907). The maximum strength of the aluminum-rich alloys is 

 28,000 pounds per square inch and of the copper-rich alloys over 100,000 

 pounds per square inch. A ductility of 50 to 60 per cent is obtained with 

 alloys containing 92 to 95 per cent copper. The maximum strength does 

 not occur at a boundary curve. Annealing increases the ductility of the 

 aluminum-rich alloys, but decreases that of the copper-rich alloys. No expla- 

 nation has been found for this diflference in behavior. 



A study has been made of the electrolytic corrosion of the aluminum 

 bronzes, and this work is nearly ready for publication. The work on the 

 constitution of the iron-carbon alloys has proceeded very slowly, and the 



